INDUSTRIAL USES OF PLANTS 391 



perfumes and is very valuable, being much in demand and 

 commanding a high price. 



Oil of citronella and lemon-grass oils are imported to the 

 United States in large quantities, chiefly from India, Ceylon, and 

 Java, where they are distilled from the leaves of the citronella and 

 lemon grass plants, members of the Grass Family. These oils are 

 produced in abundance, hence inexpensive and widely used in 

 cheap perfumes, soaps, and insect repellants. Oil of citronella 

 contains a high percentage of geraniol, the essential oil derived 

 from geraniums, and like that substance, is used as a substitute 



Fig. 249. — Leaves and fruit of the camphor tree. 



for attar of roses. Lemon grass oil yields a substance from which 

 synthetic violet is made, as well as being used as a flavoring and 

 in medicine. 



Oil of violet is extracted, by solvents and warm fats, from 

 the flowers of a violet species grown in southern Europe. True 

 violet perfume has a very delicate, sweet odor, and is very expen- 

 sive and rare, having been largely replaced by synthetic violet 

 derived from lemon grass oil. 



Camphor is by far the most important of the industrial essen- 

 tial oils. It is derived by distillation from the wood or leaves of a 

 tree belonging to the Laurel Family (fig. 249), and native to 

 southern China, Japan, and Formosa. The Japanese monopoly 



